An image sensing device encompasses at least one image sensor that senses optical signals and converts them into electrical signals, as well as an electronic circuit assemblage for processing the output signals generated by the image sensor. The image sensor and the electronic circuit assemblage are usually combined physically into one housing, which has at least one opening to allow the image sensor to sense optical signals. Image sensing devices of the species are used, for example, as an assembly in vehicle-based assistance systems, and serve there for optical sensing of the vehicle environment. On the one hand, very high clock frequencies are used in the context of digital signal processing that is often encountered today. The risk exists here that spurious radiation may get into the environment. On the other hand, components that are themselves sensitive to spurious radiation are incorporated into the image sensing device, and must be shielded from external spurious radiation. In terms of design, therefore, particular care must be taken to embody the housing to be resistant to spurious radiation. Ideally, no internally generated spurious radiation should penetrate to the outside. On the other hand, however, the inward penetration of external spurious radiation also needs to be reliably prevented. A housing embodied in radiation-tight fashion is necessary for this approach. In the image sensing devices of the species, however, the housing opening necessary for the image sensor or its optical system constitutes a system-related weak point. Because an opening is present here in the housing, the risk exists that spurious radiation might enter or leave the housing. The EMC (electromagnetic compatibility) properties are thereby disadvantageously influenced. Attempts have already been made to remedy this shortcoming by also coating the optical system of the image sensor itself with a layer exhibiting a shielding effect with respect to electromagnetic radiation. This solution has the disadvantage, however, that the optical properties of the image sensor are usually negatively affected thereby.
Japanese Patent No. JP-2002368481 describes a shielding housing for an electronic circuit that exhibits, in its edge region, spring means for resilient connection with a carrier of the electronic circuit.
Japanese Patent No. JP-2003086907 describes a flexible circuit board for an electronic circuit that carries a shielding layer and a cover layer disposed thereupon.
Japanese Patent No. JP-11239288 describes a camera housing having a window opening for an image sensor. The window opening is closed off with electrically conductive glasses.